A few years ago I discovered SDRs, and one of the first things you learn to decode is the unencrypted ADS-B signal emitted by nearly every aircraft in the sky. These are the same signals used by sites like FlightAware – which then show you real-time flight tracking and status in your Google search.
Using just a RaspberryPi and some additional hardware for only ~$50, you too can begin tracking aircraft with the open source packages available on GitHub provided by FlightAware themselves. Optionally, you can enable you feeder to send its information to FlightAware, help to provide additional coverage for your region. Linking your feeder to your FlightAware account will even upgrade you to a free Enterprise user unlocking additional features on the site.
As I began to share the link to my feeder with friends and family, I found that with the limited power of the RaspberryPi Zero, the processor would be quickly overwhelmed by the number of requests.
Statistics for the feeders I own and operate can be found on FlightAware.